You know who Judy Greer is, even if you don’t know who Judy Greer is. You may know her from her role as Cheryl in Archer, or as Kitty Sanchez in Arrested Development, or as the best friend in movies like 13 Going on 30 and 27 Dresses. You may even know her as the mom from the new “Framily Plan” commercials from Sprint. The point is, with dozens of co-starring roles in TV series and major movies, you know who Judy Greer is, even if you can’t pick her out of a lineup. This famous anonymity suits the actress just fine as she makes clear in her hilarious new biography I Don’t Know What You Know Me From: Confessions of a Co-Star.

Hailing from outside of Detroit, Ms. Greer has the work ethic of a dray horse and the sense of humor bred from the privations of the rust belt and ungodly cold winters. Her childhood, while not a large chunk of her new memoir, provides some of the funniest fodder. Like her fellow Midwesterner from across the lake, Tim Conway, Ms. Greer is more than willing to embarrass herself and expose her own foibles to make us laugh. The end result is a book that is funny and endearing. You are happy for her success and for her excitement at meeting real celebrities. Whether she is discussing spending her summers in the quaint town of Carey, Ohio, or peeing next to her far more famous co-stars, which occupies a chapter of her book, Greer has an enthusiasm for life and a wide-eyed zeal that will leave you smiling as if you were watching a basket full of puppies frolic.

In one of her best quotes, Ms. Greer notes that a family member once told her that “Work begets more work,” and in pursuit of that ideal she has relentlessly pursued roles that weren’t starring roles, but roles that would keep her working. Along the way, several of her characters have become comedy cultural touchstones. If you like Bossypants or Is Everyone Hanging Out Without Me?, you will love I Don’t Know What You Know Me From. While her career so far has been one as a co-star, something she doesn’t mind at all, you finish this book hoping she will get her chance to find that starring role and join the ranks of actresses like Tina Fey, Lucille Ball and Carol Burnett.